Provide batch position and size information inside entity operations

This is a follow-up to: https://github.com/Azure/azure-functions-durable-extension/pull/1511, https://github.com/Azure/azure-functions-durable-extension/issues/1456

Now that the `durable-extension` exposes the batch position and batch size inside entity operations, we should expose them in the JavaScript SDK as well.

Start by reading the linked pull request and issue to understand how batch position and size are exposed by the durable extension, then inspect the JavaScript SDK's entity operation API. Done means JavaScript entity operations provide equivalent batch position and batch size information, with the relevant SDK tests updated or added.

Written by the indexing model from the issue text.